New Upper 300 BLK

[Hawk36]

Do any of the participants on this forum who own and shoot the 300 AAC Blackout reload that round?

 

[wiryone1]

I do. It was the impetus that got me into reloading. I do not cast, but load 125gr Speer and Xtreme 150gr plated.

 

[Golddiggie]

I have a 300BLK in both pistol and carbine forms... Reloaded 147gr projectiles for it. Of course, I have some 110gr DRT rounds in my 'home defense' 40 round PMAG.

 

[Hawk36]

I bought 100 once fired 300 BLK cases that had been deprimed, trimmed, and cleaned. I also bought 100 - 150g FMJBT bullets. I'm using H110 powder. Since Hornady suggested the low of 14.6 g up to 17.2 g., I thought I would load at 15.5 g. I loaded 30 rounds then found out from Speer, I believe it was, gives 20 g as the top number. There is also a 2.235 length when the bullet is seated. The bullets I purchased have the cannelure, so I seated the bullet down so the crimp would grab that section. However, the C.O.L. on most rounds I reloaded is 2.060 to 2.085. Since this is a first time reloading project on the 300, I was wondering if that will produce too much pressure? So, I'm looking for advise from folks who have been loading with H110, loading FMJBT 150 g. bullets to get some help.

 

[mac1911]

I bought 100 once fired 300 BLK cases that had been deprimed, trimmed, and cleaned. I also bought 100 - 150g FMJBT bullets. I'm using H110 powder. Since Hornady suggested the low of 14.6 g up to 17.2 g., I thought I would load at 15.5 g. I loaded 30 rounds then found out from Speer, I believe it was, gives 20 g as the top number. There is also a 2.235 length when the bullet is seated. The bullets I purchased have the cannelure, so I seated the bullet down so the crimp would grab that section. However, the C.O.L. on most rounds I reloaded is 2.060 to 2.085. Since this is a first time reloading project on the 300, I was wondering if that will produce too much pressure? So, I'm looking for advise from folks who have been loading with H110, loading FMJBT 150 g. bullets to get some help.

You should follow the bullet manufactures suggested load data.
More details on the bullets. i bought the 300 upper and dies had my fun with it and sold it. i was running 165 grain cast loads.

 

[38ExtraSpecial]

I bought 100 once fired 300 BLK cases that had been deprimed, trimmed, and cleaned. I also bought 100 - 150g FMJBT bullets. I'm using H110 powder. Since Hornady suggested the low of 14.6 g up to 17.2 g., I thought I would load at 15.5 g. I loaded 30 rounds then found out from Speer, I believe it was, gives 20 g as the top number. There is also a 2.235 length when the bullet is seated. The bullets I purchased have the cannelure, so I seated the bullet down so the crimp would grab that section. However, the C.O.L. on most rounds I reloaded is 2.060 to 2.085. Since this is a first time reloading project on the 300, I was wondering if that will produce too much pressure? So, I'm looking for advise from folks who have been loading with H110, loading FMJBT 150 g. bullets to get some help.

The different manufacturers probably used different bullets for their load data.
200 grain spire point is longer than a 200 round nose
So if you seat the spire point to the suggest round nose depth you’ve upped the presssure significantly.

What was the OAL that Hornady suggested with that bullet?

 

[1919FAN]

I regularly load 168 gr bthp over 14.5 of Little gun I have no problem cutting one ragged hole at 100yds. The head pictured is soft point hunting bullet same result.

 

[Lennypeters]

I regularly load 168 gr bthp over 14.5 of Little gun I have no problem cutting one ragged hole at 100yds. The head pictured is soft point hunting bullet same result.
View attachment 236744

Could you you share what twist and gas length barrel you are using? Your results are the best I have ever seen for 300 blackout. Nice work.

 

[1919FAN]

Could you you share what twist and gas length barrel you are using? Your results are the best I have ever seen for 300 blackout. Nice work.

The barrel is a stoner 16" 1 in 8 twist from Midway carbine length gas , with a diamonhead 15" forend Yankee hill slant brake and 6-18 Bushnell scope.

 

[Hawk36]

OK, thanks for the information. I put Hornady but was actually looking at Hogdon's reloading data. It list 2.235 for the OAL using the HDY IB 150 g. bullet. I believe the bullets I have came from MidwayUSA which are FMJBT in 150 g., but not the HDY IB. So I'm not sure if the length is the same as the HDY IB bullets. I have decided to take the rounds I've already put together and tap them a few times to bring the OAL closer to the 2.235 reading. Setting them at the crimp on the cannelure is too deep. I bought a box of 20 Remington 300 AAC BLK 120 g. OTFB. Hogdon lists 125 g. NOS BT bullet at 2.060 OAL with 15.7 to 18.5C H110. Thanks for your assistance.

 

[thormx538]

I bought 100 once fired 300 BLK cases that had been deprimed, trimmed, and cleaned. I also bought 100 - 150g FMJBT bullets. I'm using H110 powder. Since Hornady suggested the low of 14.6 g up to 17.2 g., I thought I would load at 15.5 g. I loaded 30 rounds then found out from Speer, I believe it was, gives 20 g as the top number. There is also a 2.235 length when the bullet is seated. The bullets I purchased have the cannelure, so I seated the bullet down so the crimp would grab that section. However, the C.O.L. on most rounds I reloaded is 2.060 to 2.085. Since this is a first time reloading project on the 300, I was wondering if that will produce too much pressure? So, I'm looking for advise from folks who have been loading with H110, loading FMJBT 150 g. bullets to get some help.

The 150gr IB is 1.26" long, so seating at 2.235" in a case that is trimmed to 1.367" gives a seating depth of 0.392", which is fine. You want at least one bullet diameter (0.308" in this case).

15.5gr of H110 with a 150gr IB at 2.235" is 40.6k PSI -- the case is only 87% filled with powder. Seating it at 2.060 makes it a compressed load (106%) and raises the pressure to 62k PSI, which is over the SAAMI spec of 55k.

You are probably running into a situation where the bullet was designed for .308 Win, so the cannelure location is correct for that caliber but not for 300BLK. You made the right call pulling them and seating them longer. If you need to go shorter for some reason (short throat on the barrel, for example), then I would keep it under 15.3gr of H110 at 2.100" OAL, or 14.8gr at 2.060" OAL (52k PSI on both of those). '

Data is from Quickload, use at your own risk.

 

[thormx538]

OK, thanks for the information. I put Hornady but was actually looking at Hogdon's reloading data. It list 2.235 for the OAL using the HDY IB 150 g. bullet. I believe the bullets I have came from MidwayUSA which are FMJBT in 150 g., but not the HDY IB. So I'm not sure if the length is the same as the HDY IB bullets. I have decided to take the rounds I've already put together and tap them a few times to bring the OAL closer to the 2.235 reading. Setting them at the crimp on the cannelure is too deep. I bought a box of 20 Remington 300 AAC BLK 120 g. OTFB. Hogdon lists 125 g. NOS BT bullet at 2.060 OAL with 15.7 to 18.5C H110. Thanks for your assistance.

If you get me a bullet length and boat tail dimensions I can get you load data for that 120gr. The Nosler 125gr is 1.060" long.

 

[wiryone1]

Another thing to pay attention to is bullet set back depending on the expander diameter in your resizing die, brass and if you crimp. I have had bullet set back issues with Lee .300blk resizing dies. Sometimes even with crimping although a little less.

 

[Hawk36]

I just got in two 100 count in each box of Speer .308 TNT HP 125 gr. bullets. They are not BT. They measure .940. I found some 150 gr. bullets with a very narrow cannuler or line just high enough from the bottom of the bullet to allow me to crimp on that line with an OAL of 2.200 - 2.210 loading the 150 gr. I also found some 147 gr. 308 bullets which I may be able to use with the 300 BLK that have a cannuler, but not sure I can crimp there due to how deep it may seat the bulletin. I'll try later to check it out. I've loaded 10 rounds of this other 150 gr bulletin to try out to see if the rifle will eject and lock open on the last shot. 5 are loaded at 14.8 grs. of H110 and 5 at 15.0 gr of the same powder. The bullets are seated on an average of 2.190 to 2.200 OAL. I just bought the Lyman 50th Edition Reloading Book. According to it, loading for the 150 gr. FMJBT bullet the OAL should be 2.075 and powder from 14.5 to 16.2 gr. Hogdon's data for the HYD IB 150 gr. bullet is OAL at 2.235 with 14.6 to 17.2 grs of H110. I'm trying to find a middle ground! I load for 223 at 55 gr., the M1 G. at 150 gr., 123 gr. bullet for the SSK, and 150 gr, for the 7.62 x 54R 91/30 Mosin/Nagant. So, have all these different weight bullelts with different OALs, and differ weight powers is a little mind boggling with all the variables. I appreciate the help!

The bullets are in the case very tight, but I also crimp just to make sure.